Great changes___in our country during the past 20 years.A.have happened B.happenedC.have been happened D.were happened

Great changes___in our country during the past 20 years.A.have happened B.happenedC.have been happened D.were happened Great changes___in the last ten years in China.A.took place B.have taken place C.were taking place D.had taken place Great changes___in the city,and a lot of factories have been set up.是填has been happened还是have happened?为什么? 1.By the time you get back,great changes___in this area.为什么用问will have taken place?2.On his next birthday he __marries for ten years.用will have been 为什么不用has been?3.john _____now for the light in his room is still on .为什么 great great great Great great Great great great Great Great Great what changes___in your life?A.is there B.are there C.have been there D.have there been There great changes in our country.(填空题)不自然的部分是填的,O(∩_∩)O谢谢. O' Neal,the great American basketball player,bacame a (p__) basketball star when he was sixteen.